Lake Lure Dam
Lake Lure Dam is a 120-foot-tall concrete multiple-arch buttress structure in the Town of Lake Lure, North Carolina. As part of a comprehensive program of services, Schnabel performed an existing conditions assessment of this nearly 100-year-old high-hazard dam.
Lake Lure Dam’s 10 interior bays are separated by buttress walls and a gravity section on the left abutment that contains three radial spillway gates and one radial trash gate. Schnabel’s existing conditions evaluation included a detailed visual inspection, an underwater dive investigation of the upstream face, topographic and bathymetric surveys, geologic mapping of exposed rock, hydrologic and hydraulic analyses, finite element modeling stability analyses, scour analyses, and other related activities. The results of the existing conditions assessment were used to develop rehabilitation alternatives for the dam to meet NCDEQ Dam Safety requirements.
Along with the assessment, Schnabel also developed the inflow design flood for the dam to evaluate spillway capacity, revise the gate operations plan for the project, and perform dam breach analyses and inundation mapping for an Emergency Action Plan (EAP).
Schnabel has worked closely with the town of Lake Lure and the North Carolina DEQ to obtain multiple FEMA HHPD grants for engineering services. These grants helped fund the dam rehabilitation alternatives evaluation and the installation of a reservoir drain in the existing dam to satisfy NCDEQ Dam Safety requirements.
Schnabel completed the design for the reservoir drain in June 2022, subsequently supported the town with valve procurement, and then provided engineering services during the reservoir drain construction, which was completed in early 2025. The new drain system includes a new trash rack and steel bulkhead used during construction on the upstream side of the dam, a 72-inch diameter steel pipe penetration through the dam, a new 72-inch diameter knife gate guard valve, a new 72-inch diameter jet flow gate valve, and associated pipe supports and riprap armoring along the downstream channel.